Refrigerating apparatus connecting rod assembly



R. W. DOEG Nov. 8, 1960 REFRIGERATING APPARATUS CONNECTING ROD ASSEMBLY Filed Dec. 2, 1958 INVENTOR. R44? M .2 6

4Tra/Pr/ey REFRIGERATING APPARATUS CONNECTING ROD ASSEMBLY Ralph W. Doeg, Detroit, Mich., assignor to American Motors Corporation, Detroit, Mich., a corporation of Maryland I Filed Dec. 2, 1958, Ser. No. 777,736

2 Claims. (Cl. 74579) This invention relates to refrigerating apparatus and more particularly to compressor units for use in connection with such apparatus.

It is an object of the present invention to provide a new and improved drive arrangement for a refrigerant compressor.

Another object of the present invention is to provide an improved and novel arrangement for securing a connecting rod to a crankarm.

A further object of the present invention is to provide a new improved arrangement of motor, refrigerant compressor and drive therebetween.

Further objects and advantages of the present invention will be apparent from the following description, reference being had to the accompanying drawing, wherein a preferred form of the invention is clearly shown.

In the drawings: I

Fig. l is a vertical view in cross section of a motor compressor unit embodying features of my invention with a schematic arrangement of a refrigerating system shown therewith;

Fig. 2 is a view taken along line 2-2 of Fig. 1;

Fig. 3 is an enlarged fragmentary view taken along line 3-3 of Fig. 2; and

Fig. 4 is an enlarged fragmentary view taken along line 44 of Fig. 2.

Shown in the drawing is a refrigerant motor-compressor unit 10 which comprises in general a refrigerant compressor 12, a motor 14, and an interconnecting drive ar-.

rangement 16 all assembled as a unit 18 mounted and hermetically sealed Within a chamber 20 formed by a casing 22.

The casing 22 consists of an upper shell 24 and a lower shell 26 welded together by their respective flanges 27 and 29 to form the sealed chamber 20.

The motor 14 consists of a rotor 30 and a stator 32. The stator 32 is secured by suitable bolts 34 to a casting 36.

The compressor 12 comprises the casting 36 in which is formed a horizontally extended cylinder 38 within which reciprocates a piston 40. One end of the cylinder 38 is closed by a suitable cylinder head 42 within which are suitable valves (not shown) for controlling the flow of refrigerant into and from the cylinder.

The interconnecting drive arrangement 16 comprises a shaft 44 journaled in a bearing 46 formed in the casting 36. The bearing 46 extends verticallyfrom adjacent the open end of the cylinder 38 upwardly therefrom. The shaft 44extends upwardly beyond the terminated end of the bearing 46 for securemen-t thereon of the rotor 30, and beyond the rotor into an inverted cup-shaped member 48 that is secured to the upper shell 24. The opposite end of the shaft 44 extends below the lower tenninated end of the hearing 46 and is formed with an enlarged collar like section 49 and a crankarm 50. The rotor 30 is mounted on the shaft 44 so as to rest or abut States Patent ice upon the upper terminated end of the bearing 44, whereas the collarlike section 49 of the shaft is adjusted to abut the opposite or lower terminated end of the bearing so that they cooperatively limit any tendency for longitudinal or axial movement of the shaft 44.

The crankarm 50 is formed integrally with the shaft 44 and extends downwardly from the collar section 49 to be in alignment with the cylinder 38. A bushing or sleeve member 52 is journaled upon the crankarm 50 for free rotation thereon. Projecting into a radial opening 53 formed in the sleeve member 52 is a pin or stud 54, which is carried by the end cap or bearing section 56 of a connecting rod or pitman 58. The stud 54 is preferably press fitted in fixed relation into the connecting rod and projects therefrom to extend into the opening 53 which is formed slightly larger than the diameter of the pin to permit a loose fit. The bearing end 56 of the connecting rod is formed to abut upon and extend a partial distance about the circumference of the sleeve member 52 (see Fig. 3). The face of the bearing end 56 is formed with inclined sides 57 that extend to a narrow flat bearing surface 59 adapted to abut the sleeve member 52 in journaled relation therewith (see Fig. 4). However the pin 54 by its loose fit into the sleeve member will permit angular or rocking action of the connecting rod relative to the sleeve member by tethering or pivoting on the narrow fiat surface 59 to the angular limitations of the inclined surfaces 57 and the limitations of the pin 54. The bearing end 56 is held in journaled relation upon the sleeve 52 by a helically wound resilient member or coil spring 60 whose ends are adapted to hook around a respective wing projection 64 formed integrally adjacent the end 56 of the connecting rod. The opposite end 66 of the connecting rod is pivotly secured by a wrist pin 68 to the piston 40. The end 66 of the connecting rod is fitted within the walls of the piston 40 so as to limit its movement axially upon the Wrist pin 66 and to be held thereby so as to supportingly extend horizontally therefrom towards the aligned crankarm, however the connecting rod is free to pivot about the axis of the wrist pin. The wrist pin is secured preferably against rotation and is locked in a fixed stationary position to the piston by a locking pin 72. The pin or stud 54 serves to vertically support the sleeve member by the connecting rod to prevent vertical displacement relative to each other.

A lubricating system is provided which comprises in forming a spirally extended groove about the circumference of the shaft 44 within the length of the bearing 46. The lower end of the spiral groove 90 is in open communication with a central bore or passageway 92 that extends axially through the crankarm 50. In communication with the passageway 92 is a tube or conduit 94 that extends from the crankarm in a downward inward direction from the axis of the crankarrn towards and to a point centered with the axis of the shaft 44 a spatial distance from the bottom wall of the chamber 20 to provide an inlet opening 96. The inlet opening 96 is located and centered in a position whereby the passageway 94 moves concentrically therearound and about the axis of the rotating shaft 44 to effect a lifting action upon the lubricant to cause a withdrawal from the chamber 20 for conduction and distribution by the spiral groove 90 to the bearing 46. The lubricant passes from the upper end of the groove 90 through an undercut or groove 98 formed in the end of the bearing 46 to permit the return of the lubricant tothe lower portion of the chamber 20. A quantity of lubricant is stored within the lower portion of the chamber 20 at a level above the inlet 96. Lubricant from the passageway 92 is also distributed to and through a radial passageway 102 to a circumferential groove 104 formed on the crankann 50 for lubricating the crankarm'and sleeve bearing. In communication with the circumferential-groove 104 is a passageway 106 extending through the pin 54 which is in communication with an aligned passageway 108 formed in the connecting rod 58 for conducting lubricant to- Wardsand to the wrist pin and cylinder.

To secure the tube or conduit 94 to the crankarm to be carried thereby the inner terminal end of the conduit 94 is diagonally cut, see Fig. 3, and a punch or tool is entered through the radial passageway 102 to prick punch awall of the tube to form a protuberance 110 towards and into a blind end of the passageway 102. The protuberance 110 is of sufficient depth to prevent withdrawal of the conduit'from the crankarm.

A plurality of supports 112 are provided to support the assembled unit 18 to the casing 22 in a floating arrangement within the chamber 20. The supports 112 are spaced substantially equidistant from each other andeach comprises an L-shaped bracket 120 having one leg thereof secured by weld or the like to a wall of the lower shell 26, and the other leg 122 of the bracket 120 projects inwardly into the chamber 20'. Secured upon the leg 122 is a spring centering and supporting member 124 upon which rests and abuts one end of a coil spring 126, the opposite end of the spring 126 abuts against for resting thereon the casting 36. The spring 126 is located and held in engagement with the casting by a downwardly projecting centering pin 128 carried by the casting 36. The springs 124 carry the vertical weight of the assembled unit 18 while any undue lateral movement or sidesway of the assembly is limited by the shaft 44 striking against the side wall of the inverted cup 48.

During the operation of the motor and compressor, the rotation of the shaft 44 and its crankarm reciprocates the piston 40 within the cylinder 38. During the outward or suction stroke of the piston the coil spring 60 holds the connecting rod in physical contact with the crankarm to draw the piston outwardly. On the inward or compression stroke of the piston the crankarm will physically press upon the bearing end 56 of the connecting rod to move the piston inwardly, against the resistance of the gaseous being compressed by the piston, to the completion of the compression stroke.

Any suitable inlet and outlet valves,,not shown, may be provided within the cylinder head 40 to control the admittance of refrigerant gases into the cylinder and to control the outflow of compressed refrigerant gases therefrom for conduction into and through conduit 130, 132, into a condenser 134 wherein the compressed refrigerant gases are cooled and liquefied. From the condenser the refrigerant flow is regulated and metered by a small diameter conduit 136 for conduction to the evaporator 138 from which the heat laden gaseous refrigerant is withdrawn through a return conduit 140, which for a portion of its length is in thermal heat exchange relation with conduit 136, into the chamber 20 wherein any lubricant carried by the refrigerant through the system is separated therefrom for return to the lower portion of the chamber 20. The separation of the lubricant from the refrigerant is further aided by the rotation of a fan 150 secured upon and driven by the shaft 46. The gaseous refrigerant is conducted from the chamber 20 through a conduit 152 into the cylinder head for admittance into the cylinder. A metered or measured quantity of lubricant is conducted from the chamber 20 into the cylinder head for admittance with a charge of gaseous refrigerant into the cylinder through a small diameter conduit 154 which is fully set out in US. Letters Patent $2 2,236,112, issued to L. A. Philipp on March 24, 1941.

From the foregoing it will be apparent that there is provided a connecting rod to crankarm connection that permits a simple and ready assembly of the compressor without requiring interfitting of parts, or require a rigid step procedure for assembling the parts in a successive order. Furthermore the connection is one that allows a limited universal-like movement between connecting rod and crankarm, where crankshaft and cylinder are not perfectly squared at right angles to each other due to manufacturing inaccuracy and wear.

Although only a preferred form of the invention has been illustrated, and that form described in detail it will be apparent to those skilled in the art that various modifications may be made therein without departing from the spirit of the invention or from the scope of the appended claims.

I claim:

l. A mechanical connection for interconnecting a connecting rod to a crankshaft comprising a sleeve rotatable on said crankshaft, a connecting rod having a bearing section extending around a portion of the circumference of said sleeve, resilient means extending around the remaining portion of the circumference of said sleeve and having its ends secured to said connecting rod, said bearing section being formed with a substantially narrow circumferentially extending bearing surface for engagement with the surface of said sleeve to permit rocking movement of said connecting rod axially to said sleeve, a stud carried by said sleeve, said stud extending radially outwardly from the surface of said sleeve, a longitudinally extending bore in said connecting rod having an opening in said bearing section, and said stud receivable through said opening into said bore and interfitted thereinto to permit a limited rocking movement of said connecting rod axially to said sleeve.

2. A mechanical connection for interconnecting a connecting rod to a crankshaft comprising a sleeve rotatable on said crankshaft, a connecting rod having a bearing section extending around a portion of the circumference of said sleeve, a helically coiled member having ends secured to said connecting rod, said helically coiled member extending around the remaining portion of the circumference of said sleeve to resiliently urge and hold said bearing section to said sleeve, said bearing section formed with a substantially narrow circumferentially extending bearing surface with oppositely extended inclined surfaces extending therefrom, said narrow bearing surface in engagement with said sleeve and formed with said inclined surfaces to permit limited rocking movement of said connecting rod axially to saidsleeve, said inclined surfaces extending from said bearing surface axially to and outwardly from the surface of saidsleeve, a stud carried by said sleeve, said stud extending radially outwardly from the surface of saidsleeve, a bore extending longitudinally in said connecting rod havingan opening in said narrow bearing surface to receive said stud, and said stud interfitted into said opening and bore to permit and to cooperatively limit with said inclined sides the rocking movement of said connecting rod axially to said sleeve.

References Cited in the file of this patent UNITED STATES PATENTS 1,825,410 Monckmeier Sept. 27, 1931 2,179,268 Neeson Nov. 7, 1939 2,716,033 Dodge Aug. 23, 1955 2,735,613 Calling Feb. 21, 1956 2,738,687 Meile Mar. 20, 1956 2,738,919 Rusch et al. Mar. 20, 1956 2,741,424 Ploeger Apr. 10, 1956 FOREIGN PATENTS 775,801 Great Britain May 29, 1957 

